The invention relates to a seal provided between gas-carrying lines and a longitudinal member. More particular the invention relates to a seal for gas-carrying lines of an inorganic material of a yield stress and viscosity at the operating temperature that are sufficiently high to counteract leakage of the glass through the opening as a consequence of its own weight and the pressure gradient and fitted between at least two parts which must be able to move relative to one another and to installations which comprise such seals. The invention relates in particular to seals for applications in electrochemical cells and to electrochemical cells which comprise such seals.
EP-A-0,355,420 discloses a fuel cell incorporating gas-sealing soda lime glass O-rings between members of the cell stack, these permitting the individual members of the fuel cell stack to freely slide with respect to one another during thermal expansion and contraction. The sealing can be obtained by glass O-rings, which are fitted in glass reservoirs. The O-rings are formed of a soda lime glass having a melting point of 900.degree. C. and a working temperature of 1,000.degree. C.
During use of the cell stack according to EP-A-0,355,420 the clearance between several parts to be sealed relative to each other is removed and they are positioned directly on each other wherein the sealing material engages between the sealing faces.
It is not possible in this way to provide a seal which can accommodate axial movement of the part relative to a member at high temperature i.e., a seal which allows for a relatively large displacement between the part and the member.